What is the Largest Land Animal That Ever Lived?

Michael Anissimov
Michael Anissimov

The largest land animal that ever lived is likely Amphicoelias fragillimus, a sauropod dinosaur known only from a single vertebra fossil fragment, measuring 1.5 m (5 ft) in height, which has since been lost. In its complete form, it was estimated the entire vertebrae fossil would have been 2.7 m (8.8 ft) tall. A gigantic fossilized femur was also discovered near the vertebra.

Debate continues over whether the blue whale is the largest animal to have ever lived.
Debate continues over whether the blue whale is the largest animal to have ever lived.

Extrapolating from the size of the femur, and assuming A. fragillimus had proportions similar to a typical diplodocid (a family of long and slender sauropods), its estimated length (including tail) was 58 m (190 feet), much longer than the blue whale, often cited as the largest animal that has ever lived, at only 30-33 m (98-110 ft) in length. Being slender, however, its weight would have been only about 130 tons, less than the 195 ton record for a blue whale or the 190-240 ton estimate for the weight of Bruhathkayosaurus (whose name means "huge-bodied lizard"), another sauropod.

Because of the unknown whereabouts of the A. fragillimus fossils and the tenuous method of extrapolation, its claims to the title of largest animal ever are often challenged. If the fossil really existed and the extrapolation is valid, then A. fragillimus is not only the largest land animal ever to have lived, but the largest animal in general. For decades, it was thought that Brachiosaurus, a sauropod with its largest individuals possessing a length of about 29 m (96 ft), was not only the largest land animal, but approached the maximum possible weight a land animal could be (30-60 tons) and still support itself without needing to be suspended in water. Yet modern estimates of sauropod weight cite seven dinosaurs with greater weights than Brachiosaurus, most clustered in the 60-100 ton range: Sauroposeidon, Antarctosaurus, Paralititan, Argentinosaurus, Puertasaurus, A. fragillimus, and Bruhathkayosaurus.

So what you consider the largest land animal to have ever lived depends on several factors: do you believe that the A. fragillimus fossil really existed and that the standard extrapolation of its size is correct? Or is weight the most important determinant of world’s largest animal? If so, your answer could be either A. fragillimus, with a length of 58 m (190 ft.) or Bruhathkayosaurus, with a top weight approaching 240 tons. For comparison, the largest blue whale on record had a length of 33.5 m (110 ft) and a weight of 195 tons.

Because both the vertebra and femur and nowhere to be found, the claims of A. fragillimus’s size are hazy and uncertain. The extrapolations used in projecting the size and weight of both A. fragillimus and Bruhathkayosaurus are mired in controversy, so they sometimes go unrecognized as the largest and most massive animals, being replaced by the contemporary species of which we have the most knowledge, the blue whale. Reaching a consensus as to which land animal was truly the largest will certainly require locating more fossils.

Michael Anissimov
Michael Anissimov

Michael is a longtime wiseGEEK contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

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Discussion Comments


@anon43720: You are naive to believe that the blue whale is the biggest animal without realizing that we only discovered like what -- 10 percent of all prehistoric creatures? The very fact that Amphicoelias Fragillimus was documented heavily with a credible paleontologist (compared to Bruhathkayosaurus), with a single backbone being as tall as an African elephant, speaks to the position of the blue whale. In fact, if you scaled up the 8-9 feet tall backbone, then we have a Sauropod with a length of 200 feet and a weight of 122 tons at the most conservative level. Furthermore, with the fact that massive Sauropod footprints were also discovered in France and Australia, all measuring around 1.5 meters across, then if we scaled it up proportionally then we have a animal that makes your precious cetacean look like a minnow in comparison.

Just because the largest blue whale ever caught was a pregnant female, does not mean that their average weight is automatically 175 tons. If that were true, then it means that a mammal of such size would have overheated itself to death, due to the large intake of endothermic heat. To be more specific, the average weight of a blue whale is 100-85 tons -- about the same range as that of Puertasaurus and Argentinasaurus, not that of the 200 ton celebrated case.


All of you are wrong. It is the Ancient Mother because it is 120 feet but a blue whale is 100 feet.


@anon65418: the blue whale *is* marine life.


anon43720: do you mean the blue whale weighed the most or was the largest in length?(if length then that's incorrect because there are dinosaurs that were larger in length).


anon43720, I don't think anyone doubts that the biggest animal ever is the blue whale, but the question is "What is the largest land animal that ever lived?" When was the last time a blue whale walked on land? I don't think they evolved that far yet. Read the question thoroughly before you begin. Learn to read more carefully before you start calling people close minded.


to anon54172: The world was believed to be round long before Columbus. Many Greek scholars believed the earth was round over 200 years ago.


Blue whale might be the biggest, but I'll keep my money on the Megalodon or Predator X for being the biggest ones as far as marine life goes.


Does anybody know why no further research was carried out at the site where bruhathkayosaurus was found?

One of the things that makes this giant's existence so doubtful are drawings of poor quality. It seems relatively easy to travel to the south of India and finding the exact location should be even more trivial, as one could also use members of the original expedition.

Such a party could not only measure, photograph and draw the bones again, but also try to find some other remains.


you are cynical and close minded. it's close- minded people like you who ridiculed columbus for believing the world was round.


You don't appreciate the fact that are you are living in the same time with the largest and the biggest animal to ever live on the face of the earth: the blue whale. it is way bigger than your favorite prehistoric, mythical and dead animal. A.fragillimus. You are not proud of the blue whale the biggest animal to ever live whom you can see and feel, and if you're lucky enough you can also touch and swim with the biggest creature ever. instead you are trying to declare a creature that existed way before you were born (it is also uncertain whether he existed or not). stop declaring you're favorite animal the biggest animal on to ever live the earth and accept the reality that blue whales are the biggest of them all.

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